SSHD causes 100% CPU load

[Takashi Yano]

Hi everyone,

On Wed, 28 Apr 2021 07:23:02 +0300
Andrey Repin <anrdaemon@yandex.ru> wrote:

> Greetings, Christoph Lüders!
> 
> > I run cygwin 32-bit on Windows 10 Pro Build 19042.  Cygwin is 3.2.0-1,
> > openssh is 8.5p1-1.
> 
> > I use sshd to access the machine from afar.  I notice (often multiple)
> > processes of sshd.exe with 100% CPU load.
> 
> https://cygwin.com/pipermail/cygwin/2021-April/248299.html
> https://cygwin.com/pipermail/cygwin/2021-April/248309.html
> 
> > A stack shown with procexp has function names like
> > "cygwin1.dll!acl_get_perm" and "cygwin1.dll!_assert".
> 
> > Can anyone give me some advice how to proceed further?  I have updated
> > to the latest cygwin multiple times; reboot doesn't help either.

I have finally found how to reproduce this problem in my
environment. The reproduce steps are as follows.

1. Install cygwin sshd as a service and start it.
2. Connect to sshd by 'ssh user@localhost ls' using **Windows** ssh.exe.
3. Check if sshd remains with high CPU load.

I have confirmed that this issue happens in a few my PCs.

Corinna, could you please have a look?

-- 
Takashi Yano <takashi.yano@nifty.ne.jp>